254 INTRODUCTION. 
13. ovary; 14. oviduct; 15. genital bladder; 16. pulmonary chamber ; 
17. heart; 18. renal organ; 19. renal duct; 20. pulmonary aperture. 
Fig. III. Dental plate, magnified. 1. Muscle ; 2 the plate. 
Fig. IV. Penis laid open. 1. Penis; 2. thick longitudinal fold; 
3. vas deferens ; 4. retractor of penis. 
Fig. V. Spermatozoa, higldy magnified. 
Fig. VI. Digestive apparatus of H. perspective. I. Buccal body ; 
2. retractor of buccal body ; 3. oesophagus ; 4. stomach ; 5. intestine ; 
6. salivary gland; 7. ducts of do.; 8. hepatic ducts. 
Fig VII. Genitalia. 1. Testicle; 2. epididymis; 3. accessory 
gland of do. ; 4. prostate ; 5. penis ; 6. retractor of do. ; 7. ovary ; 8. 
oviduct; 9. genital bladder ; 10. cloaca; 11. right superior tentacle. 
Fig. VIII. Dissection of II. palliata. 1. Buccal body ; 2. stomach ; 
3. intestine; 4. rectum; 5. anus; 6. salivary gland j 7. liver: 8. epidi- 
dymis; 8." vas deferens ; 9. accessory gland of do. ; 10. prostate; 11. 
penis; 12. retractor of do. ; 13. ovary; 14. oviduct; 15. genital blad- 
der ; 16. retractor of buccal body ; 17. pulmonary chamber; 18. heart; 
19. renal organ; 20. supra-cesophageal ganglia. 
PLATE VIII. 
Figs. I. — VI. Helix multilineata. 
Fig. I. Digestive apparatus. 1. Buccal body; 2. retractor of do. ; 
3. lingual pouch; 4. stomach; 5. intestine; 6. salivary gland; 7. 
hepatic duct. 
Fig. II. Genitalia. 1. Testicle; 2. epididymis; 2." vas deferens ; 
3. accessory gland of epididymis; 4. prostate; 5. penis; 6. prepuce; 
7. retractor of penis ; 8. ovary; 9. oviduct ; 10. genital bladder; 11. 
vagina; 12. cloaca; 13. right superior tentacle. 
Fig. III. Penis (1) laid open to exhibit the papillary structure on 
its inner surface; 2. prepuce; 3. vas deferens; 4,5. neck of oviduct 
and vagina laid open ; 6. bladder ; 7. orifice of bladder. 
Fig. IV. Portion of the inner surface of the penis, magnified two 
diameters. 
Fig. V. Spermatozoa, highly magnified. 
Fig. VI. Spermatozoa in coil. 
Figs. VII. — X. II. solitahia. 
Fig. VII. Digestive apparatus. Same references as Fig. I. 
Fig. VIII. Genitalia. 1. Testicle ; 2. epididymis ; 2.* vas deferens ; 
3. accessory gland of do. ; 4. prostate; 5. penis; 6. retractor of do. ; 
7. ovary; 8. oviduct; 9. bladder; 10. cloaca. 
